Metal rolling mill



Jan. 12, 1932. E RBER 1,841,155

METAL ROLLI NG MILL Filed Nov. 3, 1928 if L @5.

Patented Jan. 12, 1932 PATENT OFFICE EWALD RBER, OF DUSSELDORF, GERMANY v METAL ROLLING MILL Application led November 3, 1928, Serial No. 317,104, and in Germany March 14,1928.

Devices have been proposed for conveying the work piece in tube rolling (Perrins process), in which the conveying movement is effected through the medium of a liquid column which is shifted by means ot a movable pressure member. We know also how in such devices that end of the container nearest'v the rolls, and which end receives the liquid column, is imperfectly shut oiI from l the remaining space in the container, causing atthis point towards the end of the conveying'movement the development of a temporary increase in pressure above atmospheric and thus producing a ret-arding action upon l the connecting rod. It has been further pro,-

' posed to choke the liquid column in devices of this kind during the shifting movement thereby to reduce the conveying pressure towards the end of the conveying movement.

The present invention relates to an im'- proved 'device of the character set forth, the principal object of'the invention being t0 provide means for effecting a temporary pressure above the atmospheric pressure at the end of the liquid container nearest lt-he rolls and thereby produce a more efficient and precise retarding action oft-he connecting rod, a Jfurther object ofl the invention being to provide a'device for'retarding the connecting "l" rod' at the end of its return movement. Be-

cause of the fact that the rolls impart to the rod during the rolling process such lgreat kinetic energyV that at the termination of the'rolliiig operation the movement of the connecting rod does not immediately cease. This continuationof the movement of the rod is disadvantageous because ofthe loss of time consumed in the continued'travel of the rod and its return over the unnecessarily elongated path. The avoidance of this continuation of the movement of the rod permits an increase. of the working speed about percent.

l The accompanying drawing shows diagrammatically a longitudinal section of one embodimentof the present invention.

= .Mounted for yreciprocation in a casing a is a redt)Y having a piston c secured at its inner end. A. cylinder e provided with a suitable cover e', in which cylinder a lioat f is easily reciprocable, is attached to a progection d of the lcasing a. The lioat f is disposed in the cylinder -e and is provided with an extension g adapted when moved downward, to close the communicating opening k between the cylinder e and the projectionl d, said extension fitting said opening with a little play. The front part of the casing forms a cylindrical chamber z' of less diameter than the rear part, said front and rear 6G parts communicating with each other by way of a channel 7c which channel is of the same diameter as the piston c. Mounted in cham ber z' is a. buffer spring Z of any kind, which normally retains a plate n having a number of holes m against the end of the channel k, said plate being loosely mounted on the connecting rod b. Whenever the float f, g and the piston c have descended 'to their lower positions vsli-own in dotted lines, the following chambers are formed: the working chamber I, the choking chamber II, the retardino' chamber III and the pressure chamber I1? The last named chamber contains air or gas of a pressure amounting to about twentyfive atmospheres, the other chambers being filled ,with water. The chamber III communicates with 'the chambers I and II by way of pipes equipped with check-valves o and p respectively. The casing a is closed at its rear end by means of a threaded plug f/ having a ring shaped groove r in its end face for the reception of the correspondingly formed flange s of the piston c on the rearward movement' of the piston. A check 55 valve t finally controls the communication between the chamber I and chamber II, said valve opening towards chamber II.

The operation of the device-is as follows: The lioat f, g under the pressure of the gas in chamber IV, is constantly urged downward, thus transmitting said pressure to the water in the chambers therebelow, and owing to the fact that the piston c has a larger area eX- posed to the pressure of the water at the left or rear side than at the right side thereof, the piston begins to move toward the right, and with it the rod Z2. This forward movement carries that portion of rod b which is of smaller diameter into the chamber I, while a 10" vthe pressure on the VThe piston cv and its rod however, continue to move forward because ofthe momentum stored therein.y -The water-capacity of chamber -I thus becomeslargerasa .greater length of thatportion of rod'b ofsmaller diameter takes the place of a'correspondinglength.of the portion having 'the larger diameter in chamber I, and since the water .cannot pass fromy chamber II with sufficient rapidity to lill the increased water-space in chamber VI piston c toward the end VVof vits stroke is actually decreased, so that at w the time thejpiston centers the channel 7n its .momentum is practically spent. If the diameters of .,tlre'ro'd b at theopposite -sides of the pistonev and .the .length Aof the portion g of the float are incorrect ratio,the piston c will come to'frest `iii-abutting relation with thevdiscn, anytendency ofthe `piston to con- .tinueits travel -being resisted 'by Vthe water confined in chamber III. Theidisc n is normally maintained lunder the tension of its spring in the position-shown Iin the' drawing, the provision of .thisdisc and the valved byi passes 0 and ,p being vmerely a-.safetyv measure,

i thedisc will knot ybe actuated. II-Iowever,'if,y

l pressure in chambersIand II by sinceV in thenormal operation of the device .for Yany reason the piston c should continue to move .toward the right. against the tension of the spring $1,7the water in chamber III will be forced through valve pipe p in chamber II, it being .understood that even `when the memberg has completely closed the channelh the valved pipevp is still in communication lwith chamber II, so that the pressureon the water in chamber III is transmitted to chamber II below the float, thus-causing the same to rise and compress thegas in chamber IV. Assoon astheconnectingrod b kcommences its baci*- ward movement Land lthe piston c moves away from disc ak vthe pressure on the watervr in chamber.IIIisremovedsuddenly. However, owingl -to the provision of the valve `o, no vacuum will be formed -in lchamber III because the water inchamber I will immediately pass over, so that by the time the piston has left the-channel c the pressure iin chambers I and III is completely equalized, In like manner, Athe val-ve t lserves to equalize the permitting the water to pass from chamber I to chamber kII in casefthepressure in chamber I is higher than that lin chamber I-I. When .the vpiston ina arrives at the end of its backward movement the flange s enters the groove r of the plug g, whereupon the further movement of the piston is retarded by the pressure of the water between y:it and said plug. By reason of the threaded connection of the plug gwith the housing, the said plug may be yreadily adjusted to vpermit longer or short-er strokes of the piston c to meet the requirements of varying rollingy operations. This adjustability of the plug renders possible the retardation of the rearward movement of the piston as above described, since it insures the positioning of .the plug to kcorrespond with the exact end position of the rod b.

. The forward end' of thev rod b extends beyond the end of the casing and forms a feed `rod to -which is attached the usual mandrel carrying the workw that is to be'operated on by the rolls y, in the well known manner.-

What I claim is: p

l. In a rolling mill, the combination of a casing having a. horizontal cylindrical portion and a vertical cylindrical portion, said portions together forming a pair of chambers of differentdia-meters and communicating by a channel of smaller diameter than either of said chambers, a reciprocabl-e mandrel feed bar,.a rod carried bysaid feed bar for reciprocationin said horizontal porti-on 4of the casa piston securedon that portion ofthe rod normally within the chamber of larger diameter, said piston havingvthe same dia-meter asy said channel andprovided with an `axially extending flange at one end thereof, arplug threaded in the youter end Vofsaid enlarged chamber and having in `its inner end face a circularV groove adapted to receive said flange, a cylindrical extension mountedonl said vertical portion of the casing and forming a chamber communicating through a channel ofsmaller diameter with the larger chamber inthe casing, a movable member disposedin said cylindrical extension and dividing its chamber intoan upper chamber and a. lower chamber, said upper 'chamber containing a fluid under pressure and all of the remaining chambersbeing filled with an incompressible Huid, thereby to create in all of the lower chambers a temporary pressure above atmospheric, said movable member having an extension adapted to en'tersaid last communicating channel and' close the same thereby toV discontinue said pressure'on the fluid in said lower chambers.

Q. In a rollingmill, heA combination of a casing having'aV horizontal cylindrical portion and a vertical cylindricalportion, said portions togetherforming a pair of chambers of different diameters and communicating by a channel of smaller diameter than ,either of said chambers, areciprocable mandrel feed bar,.a rod carried by said feed bar for yreciprocation in said `horizontal portion of the casing, a piston secured on that portion of the rod normally within the chamber of larger diameter, said piston having the same diameter as said channel and provided with an axially extending flange at one end thereof, a plug adjustably secured in the outer end of said enlarged chamber and having in its inner end face a circular groove adapted to receive said flange, a. cylindricaly extension mounted on said vertical portion of the casing and forming a chamber communicating through a channel of smaller diameter with the lar er chamber in the casing, a movable mem er e disposed in said cylindrical extension and dil viding its chamber into an upper c rod normally within l of smaller diameter,

viding its Vchamber into' an upper chamber and a lower chamber, said upper chamber containing a fluid under pressure and all of the remaining chambers being filled with an incompressible fluid, thereby to create in all of the lower chambers a temporary pressure above atmospheric, said movable member having an extension adapted to enter said last communicating channel and close the same thereby to discontinue said pressure on the fluid in said lower chambers. t

3. In a, rolling mill, the combination of a casing having a horizontal cylindrical portion and a vertical cylindrical portion, said portions together forming a pair of chambers Vof dierent diameters and communicating by a channel of smaller diameter than either of said chambers, a reciprocable mandrel feed bar, a rod carried by said feed bar for reciprocation in said horizontal portion of the casing, a piston secured on that portion of the the chamber of larger diameter, said piston having the same diameter as said channel and provided with an axially extending flange at one end thereof, a plug threaded in the outer end of said enlarged chamber and having in its inner end face a circular groove adapted to receive said flange, a cylindrical extension mounted on said vertical portion of the casing and forming a chamber Icommunicating through a channel of smaller diameter with the larger 'chamber in the casing, a movable member disposed in said cylindrical extension and d1- hamber and ya lower chamber, said upper chamber containinga fluid under pressure and all of Vthe remaining chambers being filled with an incompressible fluid, thereby to create in all of the lower chambers a temporary pressure above atmospheric, said movable member having an extension adapted to enter said last communicating channel and close the same thereby to discontinue said pressure on the fluid in said lower chambers, a circular perforated plate loosely mounted on that portion of said rod normally within the chamber and resilient means in said chamber normally retaining said plate in position to close the communicating channel between said chambers.

4. In a rolling mill, the combination of a casing having a horizontal cylindrical portion and a vertical cylindrical portion, said orticns together forming a pair of chambers of different diameters and communicating by a channel of smaller diameter than either of said chambers, a reciprocable mandrel feed bar, a rod carried by said feed bar for reciprocation in said horizontal portion of the casing, a piston secured on that portion of the rod normally within the chamber of larger diameter, said piston having the same diameter as said channel and provided with an axially extending flange at one end thereof, a plug adjustably secured in the outer end of said enlarged chamber and having in its inner end face a circular groove adapted to receive said flange, a cylindrical extension mounted on said vertical portion of the casing and forming a chamber communicating through a channel of smaller diameter with the larger chamber in the casing, a movable member disposed in said cylindrical extension and dividing its chamber into an upper chamber and a lower chamber, said upper chamber containing a fluid under pressure and all of the remaining chambers being filled with an incompressible fluid, thereby to create in all of the lower chambers a temporary pressure above atmospheric, said movable member having an extension adapted to enter said last communicating channel and close the same thereby to discontinue said pressure on the fluid in said lower chambers, a perforated circular plate loosely mounted on that portion of said rod normally within the chamber of smaller diameter, a spring in said chamber normally retaining said plate in position to close the communicating channel between said chambers, and valved pipes forming bypass communications between said chamber of smaller diameter and the chamber of larger diameter and between said chamber of smaller diameter and the lower chamber in said cylindrical extension.

ln testimony whereof I have affixed my 

